1. Field of the Invention
The invention deals with a control device for a yarn or thread of a textile machine having a traction member connected to the yarn, with the traction member being connectable by a coupling assembly with a lifting device, and with the coupling assembly being controlled by a piezoelectric switching member. Such a control device is for instance suited for controlling a single yarn or thread, however also for a Jacquard- or dobby loom of a weaving- or knitting machine.
2. Description of the Prior Art
Numerous control devices for the thread of a textile machine are known, thus the DE-OS 21 30 502 describes for instance a control arrangement of the above-named type in a Jacquard machine for textile machines. The Jacquard machine contains a plurality of traction members as well as a lifting device for raising or lowering traction members selected according to the pattern. A coupling arrangement serves for selecting the traction members in accordance with the pattern. A piezoelectric switching member controls the coupling assembly. However herein it is disadvantageous, that the build-up of the device is extraordinarily complicated and that the piezoelectric switching member serves only as a substitute organ, which controls the drive means which themselves cause the coupling or uncoupling to happen. Herein it is additionally impossible to monitor the operational state of the coupling arrangement.